A gyratory crusher of the above-mentioned kind may, for example, be used to crush ore and rock material to smaller sizes.
U.S. Pat. No. 2,134,885 describes such a gyratory crusher. The gap between the crusher head and the frame is sealed against dust by a sealing socket which abuts sealingly against a slide tube associated with the frame of the crusher. The sealing socket is suspended in the crusher head via a rubber skirt which absorbs the eccentric movement of the crusher head in the horizontal plane relative to the slide tube. The dust seal further allows the crusher head to be raised and lowered relative to the frame in that the sealing socket is adapted to slide in the height direction along the slide tube.
A problem with this sealing socket is that it involves lubricant loss. Without lubrication, the frictional resistance between the sealing socket and the slide tube would wear away the rubber skirt in which the sealing socket is suspended. Moreover, a constant flow of lubricant is required to prevent dust from making its way into the clearance which is inevitably present between the sealing socket and the slide tube as a result of normal manufacturing tolerances and wear. The lubricant loss consumes lubricant and contaminates the material being crushed. The dust seal is also expensive and relatively complicated to fit.
An object of the invention is to provide a gyratory crusher in which the above-mentioned disadvantages are reduced or completely eliminated.